1. Field of Invention
The present invention generally relates to the automotive, and more particularly to the storage of security data relating to a vehicle, for which a protected access must be provided to prevent forgery.
2. Description of the Related Art
A vehicle stores various data associated to it, either in digital or in analog form. Stored data are for instance the mileage, the distance to the next overhaul, the vehicle serial number, the license plate data, the date and type of vehicle defects, etc. Stored data may either be accessed visually or electronically according to its storage medium. For instance, the mileage is stored in an engine control module (ECM) and is displayed on the dashboard. The date and type of a vehicle defect are also stored in the engine control module. Such data can be read and sometimes modified using specific electronic equipment connected to the engine control module through a dedicated connector.
The engine control module commonly collects data from various devices in the car. Vehicles now include a great number of electronic control units distributed throughout the vehicle, for performing safety, control or comfort functions. Such control units are notably used to manage the transmission, the airbags, the antilock braking/ABS, the cruise control, the electric power steering/EPS, the audio systems, the windows, the doors, the mirror adjustment, etc. Some of these electronic control units form independent subsystems, but communications among others or with the ECM are essential. The ECM may notably edit data to be protected like the mileage based on information provided by other electronic control units. A subsystem may also need to control actuators or receive feedback from sensors.
CAN (for Controller Area Network) is a serial communication technology that supports distributed real-time control and multiplexing for use within road vehicles. CAN is a message based protocol. Nowadays, the majority of the produced vehicles integrate a CAN bus. The CAN standard is notably defined in the ISO 11898 specification.
The access to the security data is either not secure enough to prevent forgery or not possible for an end user without a specific diagnostic tool.
Thus, there is a need for a vehicle overcoming one or more of these drawbacks.